64125640 has 64 divisors (see below), whose sum is σ = 150459120. Its totient is φ = 24576000.

The previous prime is 64125631. The next prime is 64125647. The reversal of 64125640 is 4652146.

It can be written as a sum of positive squares in 8 ways, for example, as 8145316 + 55980324 = 2854^2 + 7482^2 .

It is a super-2 number, since 2×64125640² = 8224195410819200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 64125599 and 64125608.

It is not an unprimeable number, because it can be changed into a prime (64125647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99720 + ... + 100360.

Almost surely, 2^64125640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64125640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75229560).

64125640 is an abundant number, since it is smaller than the sum of its proper divisors (86333480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64125640 is a wasteful number, since it uses less digits than its factorization.

64125640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754 (or 750 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 64125640 is about 8007.8486499184. The cubic root of 64125640 is about 400.2615789039.

Adding to 64125640 its reverse (4652146), we get a palindrome (68777786).

The spelling of 64125640 in words is "sixty-four million, one hundred twenty-five thousand, six hundred forty".